[media] dib0700: be sure that dib0700_ctrl_rd() users can do DMA

dib0700_ctrl_rd() takes a RX and a TX pointer. Be sure that
both will point to a memory allocated via kmalloc().

Reviewed-by: Patrick Boettcher <patrick.boettcher@posteo.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

2 files changed, 16 insertions, 13 deletions

diff --git a/drivers/media/usb/dvb-usb/dib0700_core.c b/drivers/media/usb/dvb-usb/dib0700_core.c
index f3196658fb70..515f89dba199 100644
--- a/drivers/media/usb/dvb-usb/dib0700_core.c
+++ b/drivers/media/usb/dvb-usb/dib0700_core.c
@@ -292,13 +292,15 @@ static int dib0700_i2c_xfer_legacy(struct i2c_adapter *adap,
 
                         /* special thing in the current firmware: when length is zero the read-failed */
                         len = dib0700_ctrl_rd(d, st->buf, msg[i].len + 2,
-                                        msg[i+1].buf, msg[i+1].len);
+                                              st->buf, msg[i + 1].len);
                         if (len <= 0) {
                                 deb_info("I2C read failed on address 0x%02x\n",
                                                 msg[i].addr);
                                 break;
                         }
 
+                        memcpy(msg[i + 1].buf, st->buf, msg[i + 1].len);
+
                         msg[i+1].len = len;
 
                         i++;
diff --git a/drivers/media/usb/dvb-usb/dib0700_devices.c b/drivers/media/usb/dvb-usb/dib0700_devices.c
index 0857b56e652c..ef1b8ee75c57 100644
--- a/drivers/media/usb/dvb-usb/dib0700_devices.c
+++ b/drivers/media/usb/dvb-usb/dib0700_devices.c
@@ -508,8 +508,6 @@ static int stk7700ph_tuner_attach(struct dvb_usb_adapter *adap)
 
 #define DEFAULT_RC_INTERVAL 50
 
-static u8 rc_request[] = { REQUEST_POLL_RC, 0 };
-
 /*
  * This function is used only when firmware is < 1.20 version. Newer
  * firmwares use bulk mode, with functions implemented at dib0700_core,
@@ -517,7 +515,6 @@ static u8 rc_request[] = { REQUEST_POLL_RC, 0 };
  */
 static int dib0700_rc_query_old_firmware(struct dvb_usb_device *d)
 {
-        u8 key[4];
         enum rc_type protocol;
         u32 scancode;
         u8 toggle;
@@ -532,39 +529,43 @@ static int dib0700_rc_query_old_firmware(struct dvb_usb_device *d)
                 return 0;
         }
 
-        i = dib0700_ctrl_rd(d, rc_request, 2, key, 4);
+        st->buf[0] = REQUEST_POLL_RC;
+        st->buf[1] = 0;
+
+        i = dib0700_ctrl_rd(d, st->buf, 2, st->buf, 4);
         if (i <= 0) {
                 err("RC Query Failed");
-                return -1;
+                return -EIO;
         }
 
         /* losing half of KEY_0 events from Philipps rc5 remotes.. */
-        if (key[0] == 0 && key[1] == 0 && key[2] == 0 && key[3] == 0)
+        if (st->buf[0] == 0 && st->buf[1] == 0
+            && st->buf[2] == 0 && st->buf[3] == 0)
                 return 0;
 
-        /* info("%d: %2X %2X %2X %2X",dvb_usb_dib0700_ir_proto,(int)key[3-2],(int)key[3-3],(int)key[3-1],(int)key[3]);  */
+        /* info("%d: %2X %2X %2X %2X",dvb_usb_dib0700_ir_proto,(int)st->buf[3 - 2],(int)st->buf[3 - 3],(int)st->buf[3 - 1],(int)st->buf[3]);  */
 
         dib0700_rc_setup(d, NULL); /* reset ir sensor data to prevent false events */
 
         switch (d->props.rc.core.protocol) {
         case RC_BIT_NEC:
                 /* NEC protocol sends repeat code as 0 0 0 FF */
-                if ((key[3-2] == 0x00) && (key[3-3] == 0x00) &&
-                    (key[3] == 0xff)) {
+                if ((st->buf[3 - 2] == 0x00) && (st->buf[3 - 3] == 0x00) &&
+                    (st->buf[3] == 0xff)) {
                         rc_repeat(d->rc_dev);
                         return 0;
                 }
 
                 protocol = RC_TYPE_NEC;
-                scancode = RC_SCANCODE_NEC(key[3-2], key[3-3]);
+                scancode = RC_SCANCODE_NEC(st->buf[3 - 2], st->buf[3 - 3]);
                 toggle = 0;
                 break;
 
         default:
                 /* RC-5 protocol changes toggle bit on new keypress */
                 protocol = RC_TYPE_RC5;
-                scancode = RC_SCANCODE_RC5(key[3-2], key[3-3]);
-                toggle = key[3-1];
+                scancode = RC_SCANCODE_RC5(st->buf[3 - 2], st->buf[3 - 3]);
+                toggle = st->buf[3 - 1];
                 break;
         }